A timepiece including an antenna adapted to pick up an electromagnetic field bearing messages broadcast by radio has already been described in patent document EP-A-0 339 482 (U.S. Pat. No. 4,884,252) from the same applicant. In one of the embodiments shown, the antenna, entirely confined within the space bounded by the case, is formed by a coil bearing at least one turn, the axis of such coil being arranged parallel to the longitudinal direction of the bracelet. This manner of operation enables the obtaining of a satisfactory signal at the input of the microreceiver with which the watch is equipped. Such document also shows a practical construction in order to put into practice the general concept as declared, but which construction has appeared rather too simplified in terms of the progress of the development work undertaken on the watch in question, to the extent that it has been necessary to improve such construction. Within such improvements, the accent has been placed on criteria leading to a better functioning of the assembly, as for example the surface circumscribed by the turns of the winding which must be as large as possible, the general sealing of the watch and the access to different energy sources, particularly the cell energizing the radio-electric portion which must be frequently replaced.